Smoking is the most important risk factor of COPD, but only a fourth of smokers had COPD in their life. There are also healthy smokers without evidence of COPD. Investigators hypothesize that innate immunity may affect this difference between COPD patients and healthy smokers, because TLR4 is the receptor of LPS, which is the one of important substance in cigarette. Investigators will measure TLR2 and TLR4 expression in lung tissue of patients whose lung will be resected. Investigators will compare the level of expression between COPD patients and healthy smokers.